Many functions of modern devices in automotive, consumer and industrial applications, such as converting electrical energy and driving an electric motor or an electric machine, rely on power semiconductor devices. For example, Insulated Gate Bipolar Transistors (IGBTs), Metal Oxide Semiconductor Field Effect Transistors (MOSFETs) and diodes, to name a few, have been used for various applications including, but not limited to switches in power supplies and power converters.
A power semiconductor device usually comprises a semiconductor body having a number of power cells, wherein each of which can be configured to conduct a load current along a load current path between two load terminals of the device. Further, the load current path may be controlled by means of an insulated electrode, sometimes referred to as gate electrode, which may be electrically connected to a control terminal of the device. For example, upon receiving a corresponding control signal from, e.g., a driver unit, the control electrode may set the power semiconductor device in one of a conducting state and a blocking state.
In some cases, the gate electrode may be included within a trench of the power semiconductor device, wherein the trench may exhibit, e.g., a stripe configuration or a cellular configuration.
When processing a power semiconductor device, a large amount of trenches may simultaneously be produced, wherein the respective trenches may serve different purposes. For example, first trenches can be dummy trenches, second trenches may include a control electrode and yet further trenches may include a field electrode.
Besides load current carrying power cells, a power semiconductor device may comprise periphery circuitry, e.g., a sensor circuitry, a protection circuit. For example, such periphery circuitry may need to be arranged within the same semiconductor body as the power cells, but separately from the power cells.